A Soil Thermal Model for Remote Sensing

A simulation model of the heat exchange at the soil surface is used to study the effects of the soil characteristics, the initial temperature profile, and the boundary conditions on the surface temperatures. The surface temperature cycle is found to be insensitive to both the initial temperature profile and the lower boundary conditions. The result allows us to treat the soil with an analytic steady-state model as a transmission line problem. Its formulation allows us to calculate the soil conducting flux directly from the satellite temperature data, without the knowledge of the energy exchange process at the ground surface, provided that the soil thermal inertia is known. A simple inverse model can then be formulated to calculate accurately the soil thermal inertia and soil fluxes using visible and infrared satellite data. The model requires neither the linearization of the flux terms at the ground surface nor the knowledge of the lower boundary condition and the soil initial temperature profile.